Developmental abilities and disabilities in the processing of information will be studied from three converging viewpoints: Along behavioral line, an investigation of the development of the ability to encode various properties of information (physical, phonemic and semantic) will be made. This approach will be primarilyy concerned with determining possible encoding deficits displayed by children with learning disabilities. Along neuropsychological lines, the project will examine the possibility of a maturational lag in the development of hemispheric functional assymetry. A third approach will seek to relate learning problems, particularly those centering about reading, to a deficit in the abilityy to phonetically encode the sounds of speech. It is anticipated that the series of tests encompassed by these various approaches will eventually be useful in the early diagnosis of learning disabilities and in the education of children with reading and learning difficulties.